Monday, July 24, 2017

Overview

Talos has discovered multiple vulnerabilities in the FreeRDP product. FreeRDP is a free implementation of the Remote Desktop Protocol (RDP) originally developed by Microsoft. RDP allows users to connect remotely to systems so they can be operated from afar. The open source nature of the FreeRDP library means that it is integrated into many commercial remote desktop protocol applications.

We identified a number of vulnerabilities falling into 2 classes:

2 Code Executions;

4 Denials Of Service.

The first category allows code execution on the client side through a specially crafted response from a RDP server. The second category can cause the termination of the FreeRDP client. The vulnerabilities result from weaknesses in the handling of network packets sent from the RDP server. Indeed, the size of the data needed to be parsed is sent from the server without checks on the client side. An attacker can compromise the server or use a man in the middle attack to trigger these vulnerabilities.

Friday, July 21, 2017

Today, Talos is publishing a glimpse into the most prevalent threats we've observed between July 14 and July 21. As with previous round-ups, this post isn't meant to be an in-depth analysis. Instead, this post will summarize the threats we've observed by highlighting key behavior characteristics, indicators of compromise, and how our customers are automatically protected from these threats.

As a reminder, the information provided for the following threats in this post is non-exhaustive and current as of date of publication. Detection and coverage for the following threats is subject to updates pending additional threat or vulnerability analysis. For the most current information, please refer to your Firepower Management Center, Snort.org, or ClamAV.net.

Thursday, July 20, 2017

Today, Talos is disclosing several vulnerabilities that have been identified in CorelDRAW X8. CorelDRAW X8 is graphics suite used for manipulating raster and vector images and is a common alternative to Adobe Creative Cloud. Several of the vulnerabilities being disclosed today specifically affect PHOTO-PAINT X8, a raster graphics editor. Talos has responsibly disclosed this vulnerability to Corel. Corel has made a software update that addresses this vulnerability available for download.

Wednesday, July 19, 2017

Today, Talos is disclosing several vulnerabilities that have been identified by Portcullis in various software products. All four vulnerabilities have been responsibly disclosed to each respective developer in order ensure they are addressed. In order better protect our customers, Talos has also developed Snort rules that detect attempts to exploit these vulnerabilities.

Vulnerability Details

TALOS-2017-0313 encompasses multiple SQL injection vulnerabilities in ProcessMarker Enterprise Core 3.0.1.7-community. These vulnerabilities manifest as a result of improperly sanitizing input received in web requests. An attacker who transmits a specifically crafted web request to an affected server with parameters containing SQL injection attacks could trigger this vulnerability. This could allow exfiltration of the database information, user credentials, and in certain configuration access the underlying operating system.

Introduction

.NET is an increasingly important component of the Microsoft ecosystem providing a shared framework for interoperability between different languages and hardware platforms. Many Microsoft tools, such as PowerShell, and other administrative functions rely on the .NET platform for their functionality. Obviously, this makes .NET an enticing language for malware developers too. Hence, malware researchers must also be familiar with the language and have the necessary skills to analyse malicious software that runs on the platform.

Analysis tools such as ILSpy help researchers decompile code from applications, but cannot be used to automate the analysis of many samples. In this article we will examine how to use WinDBG to analyse .NET applications using the SOS extension provided by Microsoft.

This article describes:

How to analyse PowerShell scripts by inserting a breakpoint in the .NET API.

How to easily create a script to automatically unpack .NET samples following analysis of the packer logic.

Additionally, you can download a Python script (based on the WinDBG pykd extension) on our github to automate analysis of .NET. This script will be described in the article too.

Monday, July 17, 2017

In Talos, we are continuously trying to improve our research and threat intelligence capabilities. As a consequence, we not only leverage standard tools for analysis, but we also focus our efforts on innovation, developing our own technology to overcome new challenges. Also, Talos has traditionally supported open-source projects, and has open-sourced many different projects and tools that are currently used as part of our workflow like FIRST and BASS.

In this blogpost we present PyREBox, our Python scriptable Reverse Engineering sandbox. PyREBox is based on QEMU, and its goal is to aid reverse engineering by providing dynamic analysis and debugging capabilities from a different perspective. PyREBox allows to inspect a running QEMU VM, modify its memory or registers, and to instrument its execution with simple Python scripts. QEMU (when working as a whole-system-emulator) emulates a complete system (CPU, memory, devices...). By using Virtual Machine Introspection (VMI) techniques, it does not require to perform any modification into the guest operating system, as it transparently retrieves information from its memory at run-time.

Several academic projects such as DECAF, PANDA, S2E, or AVATAR, have previously leveraged QEMU based instrumentation for reverse engineering tasks. These projects allow to write plugins in C/C++, and implement several advanced features such as dynamic taint analysis, symbolic execution, or even record and replay of execution traces. With PyREBox, we aim to apply this technology focusing on keeping the design simple, and on the usability of the system for threat analysts.

This blog authored by Aleksandar Nikolich and David Maynor with contributions from Nick Biasini

Memcached - Not secure, Not Patched Fast Enough

Recently high profile vulnerabilities in systems were used to unleash several global ransomware attacks that greatly impacted organizations. These types of vulnerabilities were previously patched and could have been addressed by organizations before the attacks commenced. This is just the latest example in a long line of threats that are successful in large part because of the inability for patches to be applied in a timely and effective manner. In late 2016 Talos disclosed a series of vulnerabilities in a software platform called Memcached. After releasing the vulnerabilities Talos has been monitoring the amount of systems that were vulnerable as well as the rate at which they have been patched. This blog will give a quick overview of the vulnerabilities and discuss the unfortunate findings of the Internet wide scans that we have been conducting over the last six months.

Today, Talos is disclosing a vulnerability that has been identified in Iceni Infix PDF Editor that could lead to arbitrary code execution on affected hosts. This vulnerability manifests in a way that could be exploited if a user opens a specifically crafted PDF file that triggers this flaw. Talos has coordinated with Iceni to ensure relevant details regarding the vulnerability have been shared. Iceni has developed a software update that addresses this vulnerability. In addition, Talos has developed Snort Rules that can detect attempts to exploit this flaw.

Friday, July 7, 2017

Executive Summary

Attackers are continually trying to find new ways to target users with malware sent via email. Talos has identified an email-based attack targeting the energy sector, including nuclear power, that puts a new spin on the classic word document attachment phish. Typically, malicious Word documents that are sent as attachments to phishing emails will themselves contain a script or macro that executes malicious code. In this case, there is no malicious code in the attachment itself. The attachment instead tries to download a template file over an SMB connection so that the user's credentials can be silently harvested. In addition, this template file could also potentially be used to download other malicious payloads to the victim's computer.

Today, Talos is publishing a glimpse into the most prevalent threats we've observed between June 30 and July 07. As with previous round-ups, this post isn't meant to be an in-depth analysis. Instead, this post will summarize the threats we've observed by highlighting key behavior characteristics, indicators of compromise, and how our customers are automatically protected from these threats.

As a reminder, the information provided for the following threats in this post is non-exhaustive and current as of date of publication. Detection and coverage for the following threats is subject to updates pending additional threat or vulnerability analysis. For the most current information, please refer to your FireSIGHT Management Center, Snort.org, or ClamAV.net.

Overview

Talos has discovered multiple vulnerabilities in the freedesktop.org Poppler PDF library. Exploiting these vulnerabilities can allow an attacker to gain full control over the victim's machine. If an attacker builds a specially crafted PDF document and the victim opens it, the attackers code will be executed with the privileges of the local user.

Thursday, July 6, 2017

Executive Summary

We recently wrote about the KONNI Remote Access Trojan (RAT) which has been distributed by a small number of campaigns over the past 3 years. We have identified a new distribution campaign which took place on 4th July. The malware used in this campaign has similar features to that distributed earlier in 2017 with the following changes:

A new decoy document copy/pasted from an article published on the 3rd of July by Yonhap News Agency in Korea;

The dropper includes a 64 bit version of KONNI;

A new CC infrastructure consisting of a climbing club website.

North Korea conducted a test missile launch on 3rd July. This campaign appears to be directly related to the launch and the ensuing discussion of North Korean missile technology. This is consistent with previous KONNI distribution campaigns which have also frequently mentioned North Korea.

Wednesday, July 5, 2017

Summary

The Nyetya attack was a destructive ransomware variant that affected many organizations inside of Ukraine and multinational corporations with operations in Ukraine. In cooperation with Cisco Advanced Services Incident Response, Talos identified several key aspects of the attack. The investigation found a supply chain-focused attack at M.E.Doc software that delivered a destructive payload disguised as ransomware. By utilizing stolen credentials, the actor was able to manipulate the update server for M.E.Doc to proxy connections to an actor-controlled server. Based on the findings, Talos remains confident that the attack was destructive in nature. The effects were broad reaching, with Ukraine Cyber police confirming over 2000 affected companies in Ukraine alone.